1. Field of the Invention
The present invention relates to a disk cartridge protecting a recording surface of an accommodated disk that is an information recording/reproduction medium, from contaminants, such as dust or a fingerprint.
2. Description of the Related Art
In general, a disk cartridge accommodates a disk that is an information recording/reproduction medium and is installed in a disk drive. As shown in FIG. 1, a conventional disk cartridge 100 includes a case 101 accommodating a disk D, a shutter 110 installed in the case 101 to be capable of rotating to selectively open and shut an opening 102 formed on the case 101 so that a pickup (not shown) of a disk drive can access the disk D, and a cover 103 fixed on an upper portion of the case 101. The disk cartridge 100 further includes a hole 103 formed on the cover 103 for disk exchange and clamping, and an escape prevention lever 103a installed at the cover 103 to be capable of sliding to prevent the disk D from escaping through the hole 103b. Thus, when the disk D is installed, the escape prevention lever 103a is pulled back not to interfere with the disk D. After the disk installation is completed, the escape prevention lever 103a is pushed forward so that an end portion of the escape prevention lever 103a prevents the disk D from escaping through the hole 103b. 
When the disk cartridge 100 accommodating the disk D is inserted into the disk drive, as shown in FIG. 2A, an opening lever 120 installed at the disk drive pushes a locking piece 111a so that a protrusion 111c of the shutter 110 is unlocked from a groove 101a of the case 101. Then, the opening lever 120 pushes an interference piece 111b to have the shutter 110 pivot with respect to the case 101. The shutter 110 includes first and second shutter portions 111 and 112 respectively installed to pivot around left and right pivot shafts 110a and engaging each other through an engagement gear portion 113. As the first shutter portion 111 incorporated with the interference piece 111b rotates clockwise, the second shutter portion 112 rotates counterclockwise so that the first and second shutter portions 111 and 112 are separated from each other to open the opening 102. Then, a turntable (not shown) and a damper (not shown) of the disk drive pass through the opening 102 and the hole 103a, respectively, to clamp the disk D. A pickup (not shown) accesses a recording surface (information area) of the disk D to perform an information recording and/or reproducing process. Although not shown in FIGS. 1 through 2B, a torsion spring elastically biasing the first shutter portion 111 in a counterclockwise direction on FIGS. 1 through 2B, that is, in a direction to close the opening 102, is installed between the first shutter portion 111 and a bottom surface of the case 101. When a force applied by the opening lever 120 is removed, the shutter 110 is returned to an original closed position.
However, in the above structure, since the shutter 110 is installed in the case 101, and the disk D is placed on the shutter 110, during an opening/shutting operation of the shutter 110, the shutter 110 contacts the recording surface of the disk D (a lower surface of a disk in the drawings) so that the recording surface of the disk D may be scratched by the shutter 110 to be damaged.
Also, dust can be introduced through the hole 103b of the cover 103. Of course, since an upper surface of the disk D facing the hole 103b is not a surface for recording, direct contamination due to the dust does not occur. Nonetheless, as the dust is introduced into the case 101 and placed on the shutter 110, the dust on the shutter 110 adheres to the recording surface of the disk D during the opening/shutting operation. Therefore, an improved structure to protect the information area of the disk D is needed.